Jack Stollsteimer, a Democrat of Haverford Twp., Delaware County, shattered more than 150 years of history Tuesday night by winning election as the first democrat to be elected Delaware County District Attorney.

Stollsteimer’s opponent, Katayoun Copeland, a longtime Radnor resident, was appointed in January 2018 to serve out the remainder of former District Attorney Jack Whelan’s term when he was elected to the Delaware County Common Pleas Court.

She previously served for 19 years in the Delaware County District Attorney’s office, prosecuting an estimated 4,000 cases as chief of drug enforcement and heading the office’s Criminal-Terrorism Unit. She took a post with the U.S. Attorney’s office in Philadelphia in 2011, where she prosecuted international drug operations, large-scale racketeering conspiracies and attempted murders.

Stollsteimer also previously served as an assistant district attorney in 2000 before becoming a policy analyst and special assistant U.S. attorney for the Project Safe Neighborhoods gun-violence initiative in 2001. In 2004, he was appointed assistant U.S. attorney and assigned to lead a gun violence task force. Stollsteimer was appointed deputy state treasurer for consumer programs in 2017.

According to preliminary results, Stollsteimer will serve as the Delaware County District Attorney.

This is a developing story.